Issue with Proximity Sensor during calls

Replaced iPhone, seems to work OK on short calls. On longer calls > 20 minutes proximity sensor is failing.

same thing I've experienced on all 4 on my new iphones. I kept calling tech support telling them the new one did the same thing and they kept saying that I need to change it out for a new one. Finally, after the fourth one they said that they are no longer accepting exchanges for prox sensor issues and that the engineers are investigating the problem.

Translation = learn to live with it or return it.

Apple has seriously disappointed many with this magical new phone. I've been an apple consumer for years and own thousands and thousands of dollars of their products and have never had issues like I'm haing with the new iphone 4. I can only conclude that they have changed as a company and have grown way to big for their britches. They could fix it all by being responsive and communicate to the 1.7 million customers who have spent money on their phone but instead they hide in cupertino and continue their excessivly, secretive mojo.

I returned my iPhone 4 today for a refund. I've owned every iPhone thus far and have been a loyal Apple stockholder.

I experienced the proximity sensor issue on every call. I dropped every other call.

There is no excuse for such poor quality. I have downgraded to the 3GS.

Having the same problem on my iphone 4. Proximity sensor constantly not working effectively. Its so embarrassing for me because people are slating me for getting the new iphone. I've already returned one already and apple replaced it with a "new" one. i say "new" because the phones usage was 25 days and so many hrs and it had a few folders created. so i dunno whether the phone they replaced is actually a brand new one and not just another returned iphone. And guess what, the "new" phone i got replaced is doing the same thing: muting calls, hanging up calls then dialling a different number etc.
whats really funny or annoying is that my girlfriend has an iphone 4 and theres nothing wrong with it!!!!! the only difference with my phone and hers is that she ordered hers from apple direct for 600 pounds and i got mine through orange (i know). oh and hers is a 32gb and mine is a 16gb. so i dunno whether this problem is because its a 16gb or because my girlfriends one is direct from apple...........

I may have discovered another piece of the puzzle ( I think). I have wondered why different phones and/or individuals seem to get different results with the proximity sensor issue on the Iphone 4. Some people feel that it is heat related or dependent upon how much time has expired on the phone call before the problem starts. I had even noticed that my Iphone 4 will respond differently. I have experienced different trip points (distance) at times to deactivate and reactivate the display.

The following is based upon testing that I completed and may or may not be the actual reasons that we all experience different results. However, this could explain it. You can test it for yourself as verification and form your own opinion.

It appears that Apple Engineers have decided to use a dynamic averaging method to constantly adjust the sensitivity (trip point in distance) of the proximity sensor. The distance away from the screen to trip the proximity sensor is constantly changing. It seems that they are using an averaging method to adjust the sensitivity of the proximity sensor (trip point).

I will try to explain my findings as best I can. I am going to use a simple number scale to represent distance from the screen. The numbers can be any measurement scale you wish to use (metric or imperial). I will use a scale of 0 – 60 units for distance as a simple example.

For example, let’s say that you initiate a call or etc and the proximity sensor deactivates the display. Let’s say that you first place your head at 60 units away from the display and the display is turned off by the proximity sensor (so far so good). If you move your head between 50 units and 60 units (never moving closer than 50 units), then the Iphone 4 will create a new trip point at 55 units. What does this mean? This means that if the screen becomes active again (you move past the initial trip point with your face), then you will have to position your head at 55 units now before the proximity sensor will deactivate the display. A distance of 60 units will no longer trip the display to deactivate. Therefore, you will have to be closer to the display than before so that it will deactivate again.

Another example, if you initiate a call and first place your head at 40 units and the display is deactivated (so far so good). If you move between 40 units and 30 units from the screen, then it will require that you place your head at 35 units to re-deactivate the screen should it activate again. The result is that you now have to be closure to the display to trip it.

How does this affect us? If you place the display very close or touching your face and hold it fairly stable for a while, then the sensitivity is now averaged down. Meaning it requires a slight movement or distance change to reactive the display again. This allows time for your face to touch the screen and press the various buttons.

Different user habits can create different effects. It depends upon how close you initially place the display to your face when the call is started and how much you move the phone during the call. A person that places the phone near their face and holds it relatively stable would have a reduced range before the display will start reactivating again. Basically, they will experience a lower sensitivity (distance) to reactivate the screen. A person that moves the phone constantly in and away from their face may actually have a higher sensitivity (distance) away before the display activates and they start pressing buttons on the display. This dynamic average method Apple is using will create different distances for different users. They should have made the process constant and none of may be experiencing these problems.

I still go back to my original statement. The previous Iphones did not seem to use this type of method. The previous Iphones appear to use a static method during the entire phone call. If Apple will change the distance trip point and eliminate this dynamic averaging method for the sensitivity (trip point in distance), then the problem could be resolved.

That was a great explanation! Sorry if this is a repost, but this is the best vid I found illustrating the problem in general.

http://www.youtube.com/watch?v=8gFqAEuioi4

Maybe someone could do a more specific test by using different initial distances to really see if that's what it is. My hunch is telling me you are correct though. The longest call I've had so far is 25 min. I definitely had more time to switch hands and move the phone around. Fortunately, my cheek only put that call on hold once. I muted it once in a 10 min call where I was doing other stuff around the house. I've had about 5 calls less than 10 min long - one where I consciously held the phone very still (right after discovering this thread, lol) & another where I just woke up laying in bed (definitely wasn't moving around then lol) and no problems! The other 3-4, I'm assuming, just didn't last long enough for me to move around or switch hands, which could correspond with the correlation between the increasing length of the call and the issue.

As far as temperature goes, I only noticed some heat near the end of my 25 min call - not really that hot at all though.

I too am having serious problems with this. I'd like to know if Apple has acknowledged the issue. This should be a simple software fix. I'd just like to know before I return the phone.

This new FaceTime feature *****! Why in the world would I want to dial and hit buttons with my cheek while I'm on the phone with something else! Is there any way to turn off the FaceTime so I can just talk normally on the phone without my cheek and chin hitting mute and other buttons?

This has NOTHING to do with FaceTime. You may be hitting the FaceTime button, but even if there was no FaceTime, you'd just be hitting the hold button that used to be there.

Message was edited by: WVUFloydFan

I too am having this issue. this is my 2nd iphone. i had the 3g and upgraded to the 4 day of launch. i have hung up on my parents and my wife numerous times and put them on mute and also started changing ring tones of people on my contact list while on a call. i have had numerous dropped calls and audio cutting in and out on every single call made or received. i have the 32Gb model and i stood in line for 7.5 hours to get into the apple store to purchase this phone. sad to say i am a true apple lover and have been for many years but due to these issues i have decided to swap over to the droid x as soon as it comes out.

I did do specific measurements to verify. I used generic units in my previous post to make it easy to explain (or at least easy for me to explain).

If you trip the proximity sensor quickly at 1.5 inchs and then move your face or etc between .5 inches and 1.5 inchs from the display, then the new trigger point will be at around 1 inch. This means that if for some reason you position your face so that the display is activated again, then the next trigger point to deactive the display will be at 1 inch and no longer at 1.5 inches as it started and so on. The proximity sensor has just become more sensitity to movement.

The proximity sensor can be reset by moving your face or etc out of the measurment range of the sensor. This is past two inches or so. So, for example, moving the phone from one ear to the other would reset the sensitivity (trigger point). A new average point would be created over again.

So it appears that people that hold their phone very stable (not moving the phone closer or away from their face) may have a better experience. The sensitivity would be short. They would never know it, because the are not moving the phone around.

A person that moves the phone from ear to ear often or someone that at least moves it past a couple of inches away from their face often may not seem to have the problem as often.

People that keep the phone near their face and may reposition it a little from time to time (so that it moves only sligt amounts away from their face each time) would experience the proximity sensor issue more often.

Dude,

You are giving apple way too much credit, I seriously doubt they created a complex algorithm for a proximity sensor. I think what you are seeing is a faulty, or defective, or heat sensitive, sensor that is not behaving consistently.
Also your theory does not explain why 3GS phones operating on OS4 work fine. Such a proximity sensor algorithm would be software based not hardware based.
Very creative Idea though...
Do you work for apple?

I too am having the proximity sensor problem with iPhone 4. What is most disturbing to me about this is that Apple does not acknowledge it as a problem. Does this mean it cannot be fixed?

I currently do not and have never worked for Apple.

I have an Iphone 3G, 3GS and Iphone 4. The 3GS is running the new Iphone OS.
The 3GS does respond differently than the Iphone 4. First, I think that the sensor range is better on the 3GS. I do not know, but it could be the difference between one (Iphone 4) versus two (3GS) sensors. I have tested both and the 3GS (at least mine) responds much better than the new Iphone 4 with the new Iphone OS.

I am sure that the OS can determine what type of Iphone it is running on. It could setup and install slightly different depending upon the version of Iphone. So it would be possible for Apple to have a different response setup for one Iphone type versus another. I asked the Manager at my local Apple store why the Apple support people always recommend reinstalling the OS as a new phone when people have problems. I asked your question (more or less). It is the same OS I stated to her. She explained to me that it is the same OS, but it is setup different on each type of phone that it is installed on. So when a person does a restore from a backup (like from a 3GS to an Iphone 4) the OS is the same, but the settings internally are not. The older settings from the older phone could be restored on the new generation of phone. This could create problems! This answer seemed plausible to me.

I happen to work as an Engineering Manager for a company that designs electronics and software. We use Linux for the OS on our devices and M.S. Windows for the PC side. We design IC chips (some people may call them EEproms) in our devices that tell us what serial number, hardware version and other parameters are in the device. Our firmware (software) running on the device can read these chips and determine what hardware version and etc it is running on. From that point we can make the firmware operate differently on different devices. It is the same firmware (software) that the user installs on each device. We can turn on a feature for one user and turn it off for another. The reason is that an older version of hardware may not electronically support a new feature or etc. Therefore, we have to be able to identify this and deactivate certain functions and etc as may be required. Also, this gives us a way to track the device even if a customer rips off the serial number or etc from the housing.

Apple does the same on the Iphones. Notice how an Iphone always knows the serial number, lifetime call time and certain other information no matter what is done to the phone. Apple uses some similar means to store certain information in their Iphones. So the same OS could install on two different versions of Iphones and function differently. This makes sense to me. That is why I accepted the response I received from the Apple Store Manager.
This is why extensive testing is required on a product. No matter what the real cause of the proximity issue may be. Apple should have found it during their beta testing. Most companies will lock down the hardware and software modifications at some point and shift totally to beta testing and then final release. Once beta testing is started they usually do not make any more modifications in the software or hardware design. The reason is that a slight change could create a huge bug! Also, to do it correctly the beta testing phase has to be repeated again. This would extend the length of time to get a product released to market.

Look at how they may have designed the proximity electronics. The following is total speculation on my part. The actual proximity sensor is most likely IR. It contains a transmitter and a receiver. The signal is transmitted, reflected and the detector measures the signal response. This circuit would create some type of voltage response based upon the amount of signal received. An electronic circuit could be designed to measure this voltage and automatically activate or deactivate the display at some level. A circuit could be designed so that the voltage response could be measured by the software and the software controls the display circuit (on/off). This would be similar to the way the GPS or other sensor in the Iphone work. They are electronic circuits, but the software can receive values from them and react based upon programming. So Apple could have designed this method a couple of different ways (software or hardware).

1439 Reply's to this and still no sound off from APPLE?

Steve, I own over 43 APPLE computers and 14 new IPHONES and we MUST use bluetooth as we bump every call we make unless we hold the phone funny, upside down, and put the call on speaker phone.

Please do not ignore this issue, 93 pages of people with the same problem.